1. Field of the Invention (Technical Field)
The present invention relates to luggage, particularly wheeled luggage, and specifically a stable, easily pushed or pulled, two-wheeled luggage case.
2. Background Art
Wheeled luggage cases are now the norm in the art of luggage making, and luggage without wheels have become the exception. Even luggage cases small enough to carry on board aircraft commonly are wheeled to ease the transport of a loaded case. The most popular type of wheeled luggage case currently is the upright case, which is pushed or towed with the longest or major dimension nearer to vertical than horizontal. Typically, upright cases are equipped with a wheel handle at the top end of the body of the case and a pair of wheels at the bottom edge of the back of the body. At rest, the case may sit in an upright position upon the wheels and a pair of legs or glides. To roll the case, the user grips the wheel handle and tips the case to lift the glides from the supporting surface and manually steadies the case upon the wheels for pushing or pulling.
Commonly in the art, the wheels on upright cases are relatively small. Small wheels of three inches or less in diameter are normally used to minimize weight and cost. One of the parts at highest risk for breakage on a typical luggage case is the wheels, and since small wheels do not extend far beyond the protective contours of the case, they are perceived as posing a reduced risk of breakage during handling in automated baggage systems and the like. Small diameter wheels also are frequently mounted in swivel casters upon upright cases.
However, small wheels present a substantial drawback in that they are vulnerable to "chocking," that is, the tendency for wheel rotation abruptly to stop if the wheel encounters a surface irregularity in the ground or floor. Pulling a small-diameter wheeled luggage across a bus terminal parking lot, for example, can be fraught with difficulty if the lot has numerous cracks or pebbles. When a small diameter wheel hits a crack, the luggage case may immediately stop rolling, to the frustration of the user. This undesirable chocking effect, which is amplified when the case is heavily laden, is also observed when a small-wheeled case is pulled across thick pile carpets, elevated door thresholds, elevator thresholds, etc. Small-diameter wheels also make it more difficult to pull a wheeled case up and over a curb or stair tread, since the full weight of the case effectively must be lifted, the smaller wheels being unable to roll over the edge of the curb or stair.
It is known that large wheels are less easily chocked by supporting surface irregularities. A larger diameter wheel tends to roll up and over elevated obstructions such as small stones and the like, while a small diameter wheel encounters the same obstruction and comes to a stop. Similarly, while small diameter wheels tend to fall into cracks, large diameter wheels are able to "span" and roll across cracks in the supporting surface.
Previously in the art of luggage making, however, there has been a resistance to the use of larger diameter wheels. Large wheels have been shunned as unattractive on luggage. Considerations of weight and overall case size have discouraged the use of large wheels. Large wheels have also been stigmatized, to some degree, as vulnerable to breakage when they "stick out" too far from the main body of the case. Efforts to hide and/or protect large wheels frequently have involved the placement of the wheels "inside" the body of the case, at some sacrifice of the case's internal cargo capacity. Large wheels mounted on the outside of the body of the case to minimize intrusion in the interior, though, may be mounted upon axles cantilevered from the body of the case, resulting in flimsy wheel assemblies subject to bending and breakage especially in cases heavily loaded.
A need remains, therefore, for a wheeled luggage case offering the advantages of large wheels while ameliorating or eliminating the disadvantages thereof. Against this background, the present invention was developed to provide a large-wheeled luggage case that is aesthetically attractive, comparatively lightweight, durable, and yet comfortably maneuverable while been pulled or pushed across an irregular supporting surface.
It is also known in upright cases of the type discussed above, whether these cases have large diameter wheels or not, that the main packing compartment is sometimes difficult to pack in a way that the goods are easily accessible when the case is opened up, for example, in the upright position when it's standing on the pair of wheels. Prior attempts to organize this with protruding shelves which divide the interior of the case have met with some success. Also, the use of a divider pad, that is, a stiffened panel that is sized to clip across the full width and height of the main packing compartment, also helps to organize the otherwise cavernous interior. However, past attempts to integrate these two organizing features, the shelves and the divider pad, have resulted in some people removing the divider pad in favor of only partly organizing the goods packed therein. Also, unless used together, the divider and shelves are of marginal help in preventing the carefully packed goods from accumulating in the bottom of the case and resulting in wrinkles in the packed goods at the end of the trip.